import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: WHY
 * Date: 2023-03-02
 * Time: 21:55
 */
public class testdemo {

    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        int n=scanner.nextInt();
        int i=0;
        for(i=2;i<n;i++){
            if(n%i==0){
                System.out.println("不是素数");
                break;
            }
        }
        if(n==i){
            System.out.println("n是素数");
        }
    }
}
